Continuity mistake: As the Marvin's listen to the tape recording of the UFO, Dr. Marvin stops the recorder and uses his finger to re-wind it. If you look closely he goes way past the spot where the sound started. (00:08:00)
Continuity mistake: Carol and Dr. Marvin finally get to "Operation Sky Hook" and they're driving the exact same make and model car as they were in the previous shot. The only thing that has changed is the license number, which was AV-27-X3 and is now AV-35-B7. (00:06:55)
Continuity mistake: After they pull over to the side of the road to look at the UFO Dr. Marvin gets back into the drivers side of the car and his jacket is draped over the center of the front seat. In the next shot it disappears. (00:06:00)
Continuity mistake: The UFO flies over the Marvin's car as they approach "Operation Sky Hook" and causes them to pull over to the side of the road. When the doctor gets out of the car they're in a different place than they were in the previous shot. (00:05:35)
Continuity mistake: The Marvin's pull over to the side of the road to look at the UFO and the upholstery of their car changes from black to white between shots. (00:05:30)
Continuity mistake: The aerial shot of Carol and Dr. Marvin driving up to "Operation Sky Hook" shows a flat desert. In the next close-up shot of them inside the car we see a hilly terrain through the rear window. (00:02:40)
Continuity mistake: Between the second and third shot of the movie the cockpit of the jet changes in the close-up. (00:00:20)
Continuity mistake: As they sit enjoying Carol's barbecue the umbrella on the table behind them is tilted in a different direction between shots as a soldier drives up in a jeep with a message for Dr. Marvin. (00:13:15)
Continuity mistake: One of the three trucks used in the movie with the magnetic interference units on them has a distinctive kink in it's dish, and we see this truck destroyed by the aliens. Several shots later when the battle is over this truck is back again. (01:19:05 - 01:20:55)
Continuity mistake: We see the head of the alien up close twice and each time the gravel underneath is raked differently. (00:56:25)
Continuity mistake: After they've destroyed the alien craft spotted flying around inside of the Belmont lab, Dr. Marvin and the others decide to pack up and leave. Even though the sound has been edited out, the car and truck are already running with their headlights on before anyone gets into them. (00:51:50)
Continuity mistake: The Motorcycle cop that is taken up into the alien spaceship with them asks, "What team has won the most World Series?". When he asks the question he takes his hat off which leaves a dark impression on his forehead, in the next shot it's gone. (00:41:40)
Continuity mistake: After they pull over to the side of the road to look at the UFO, Dr. Marvin gets back into the drivers side of the car as Carol slides unobstructed from the drivers side over to the passenger seat. In the next shot the tape recorder is sitting there between them. (00:05:55)
Continuity mistake: After they pull over to the side of the road and look at the UFO, Dr. Marvin gets back into the drivers seat and hands Carol a Chesterfield from his shirt pocket. In the previous shot he didn't have anything in his shirt pocket, in fact he didn't even have a pocket on his shirt. (00:06:00)
Continuity mistake: The UFO flies right over the cockpit of a United Airlines jetliner but does not leave a shadow. (00:00:45)
Continuity mistake: Dr. Marvin and Major Huglin leave The Internal Security Commission meeting together and drive from The Pentagon to the doctor's hotel. Even though we just saw Carol and Dr. Marvin fly into Washington in an airplane he's driving the exact same make and model car that they were in at "Operation Sky Hook". Even the California license number AV-35-B7 is the same. (00:30:00)
